Drives of the foregoing type, which are also known as suspended drives, have been known for a long period of time. German Pat. No. 838 452 has as its subject matter a drive of the described type in which the elastic coupling is formed by a rubber disk which surrounds the wheel-set axle and is connected, for example, vy vulcanizing, on one side with a disk-shaped flange which is secured on the hollow shaft and on the other side with a disk-shaped flange which is mounted on the wheel-set axle. (Here and hereinafter, references to "rubber" include plastics and similar materials with comparable characteristics.)
All double-axle drives of the above-described type are characterized by the elastic couplings having to not only transmit torque, but also to absorb the reaction moment of the motor and to carry resiliently the entire weight of the drive aggregate. In the case of the design of the elastic coupling which is discussed here, the rubber is stressed mainly by shear stresses through the weight and the mass forces which occur during the driving operation, namely in a plane which lies perpendicular to the wheel-set axle. In order not to permit the drive unit to sag too much with respect to the wheel-set axle, the rubber disk must be relatively narrow and hard. Through this, however, the negative effects of the shear stresses are increased and the lateral spring action, in the direction of the wheel-set axle, is worsened. A further important disadvantge is that the wheels must be removed from the axles during replacement of the rubber disks.
This disadvantage, which very much interferes with operation, is avoided by a coupling with divided elements, as is known for example from German OS No. 23 32 281. A hub mounted on the hollow shaft and a hub mounted on the wheel-set axle each have a number of radially outwardly extending arms which are arranged alternately, one behind the other, and are each placed between two arms of a square-shaped elastic block. The elastic blocks can be individually removed and inserted without the wheels having to be removed from the axles. This type of coupling is very stiff in the plane perpendicular to the wheel-set axle. In a lateral direction it is softer than the construction with the rubber disk, but the blocks are exposed to shear stresses. A further disadvantage is that the elastic blocks, during installation, must first be initially tensioned in an auxiliary mechanism so that they can be moved into the space between the arms, which space corresponds with the initial tension required for operation.
Therefore, the basic purpose of the invention is to produce a double-axle drive of the above-described type which does not have the mentioned disadvantages and thus is easy to manufacture and service, the elastic elements of which are exposed to little or no shear stress.